Re: [gentoo-alt] Re: [PREFIX] Bootstrap stable?

[Guilherme Amadio]

Hi François,

> On 3 Apr 2019, at 22:51, Francois Bissey <francois.bissey@×××××××××××××.nz> wrote:
>
> Hi,
>
> As someone who was involved until very recently in installing software
> on the New Zealand national facility I feel I should take exception to some
> of these comments.
> To put things in perspective
> 1) I am using Gentoo since 2003
> 2) I am a regular contributor to the science team and maintain sage-on-gentoo
> 3) I pushed for a while to have prefix working on ppc64 (the hardware was
> at some time part of the national facility above)
> 4) I have contributed code to spack and help fix some issues with libtool
> in spack and occasionally suggests fix to some packages.
>
> Gentoo prefix is awesome but some areas are not as flexible as spack.
> Mainly because it is designed like a gentoo distro as a single tree
> install. Everything goes into one prefix.
> What spack allows you to do (and that is a usual requirement):
> allow and maintain an unhealthy forest of softwares:
> 1) across several versions
> 2) across various compilers
> The whole dynamically loadable via “modules”. Each bits in its own bubble.
> This also has limitation of course.
> Gentoo has slots that does multiple versions of some software but it is
> not a universal feature (nor should it be on the point of view of a distro).
> Basically if you want to reproduce some the scenarios managed by spack you
> need multiple prefix.
> That’s not to say spack wouldn’t benefit from a dose of gentoo and vice versa.
> But some Gentoo features have been voluntarily avoided :(
>
> Now prefix was very useful to me to offer a base userland on top of SLES 11.1
> (which couldn’t be updated for various reasons) that was much more recent and
> feature-full than I would otherwise have had access too. And then I could put
> something like spack on top if I wanted to.

This scenario is exactly what I was proposing in the HSF packaging meetings, to
have a base userland installed with portage on top of which one could manage
the end user applications with spack if need be, or nix, or any other tool.

I think stacked prefix can solve a good part of the combinatorial use case that
spack was created for, but for now the best solution for such cases is probably
a combination of prefix and another package manager aimed at combinatorial installs.
But an overlay with slotted scientific packages could also be interesting to explore
(i.e. the slot could be used to just adjust the prefix to $EPREFIX/lib/<pkg>/<version>).
That would probably work well enough for gromacs and other similar tools.

Cheers,
-Guilherme

>
> François
>
>> On 4/04/2019, at 07:57, Guilherme Amadio <amadio@g.o> wrote:
>>
>> Hi Jon,
>>
>>> On 3 Apr 2019, at 12:56, Jon Woodring <woodring@××××.gov> wrote:
>>>
>>> Looking at the GSOC, I noticed that it’s mentioned that one of Prefix’s goals is to bring Gentoo to HPC, and actually that’s where I was trying to use Prefix.
>>>
>>> I don’t know if you’re familiar with Spack https://spack.io/, but I was exploring using Prefix and portage, because it has a larger community and more features.
>>
>> Yes, I’m advocating for using prefix for HEP (at CERN) and HPC in the HSF packaging group,
>> but I think that they are unfortunately more interested in using spack, even though it
>> doesn’t seem to be mature enough for what is its intended use. In any case, since you are
>> from LANL, if your cluster has CVMFS mounted (i.e. /cvmfs/sft.cern.ch), then you can already
>> use prefix! I have prefix installed in CVMFS, which I discussed at CHEP:
>> https://indico.cern.ch/event/587955/contributions/2938043/
>>
>> Just run /cvmfs/sft.cern.ch/lcg/contrib/gentoo/linux/x86_64/startprefix to get started.
>>
>> In principle, there’s nothing preventing you from using ACCEPT_KEYWORDS=‘x86_64’ in your
>> prefix configuration. It’s just not tried by anyone yet. We all use ~x86_64 for now for
>> prefix on Linux. On Mac OS X there’s no stable keyword, ~*-macos are the only ones.
>>
>> My first talk about prefix for HSF packaging group:
>> https://indico.cern.ch/event/672745/
>>
>> Other related links:
>> https://hepsoftwarefoundation.org/workinggroups/packaging.html
>> https://groups.google.com/forum/#!forum/hsf-packaging-wg
>> https://indico.cern.ch/category/7975/
>>
>> Cheers,
>> -Guilherme
>